Among the many functions provided by networked electronic devices, navigational assistance for vehicle navigation has become increasingly popular. In particular, drivers and passengers often use their telecommunications device, a dedicated portable device or a built-in device to provide driving assistance while in a vehicle. Many such systems operate via GPS to determine the location of the user's vehicle.
However, GPS guidance is only usable where GPS signals can be and are being received. In locations where obscuration or interference renders GPS unusable, navigation assistance becomes unavailable for GPS-based systems. While inertial navigation systems can sometimes replace GPS-based navigation for short periods, such replacement facilities do not necessarily directly measure vehicle parameters, and as such are subject to increasingly drift and other problems as the period of use becomes extended.
Before proceeding, it should be appreciated that the present disclosure is directed to a system that can eliminate some of the shortcomings noted in this Background section. However, any such benefit is not a limitation on the scope of the disclosed principles, or of the attached claims, except to the extent expressly noted in the claims. Additionally, the discussion of technology in this Background section is reflective of the inventors' own observations, considerations, and thoughts, and is in no way intended to accurately catalog or comprehensively summarize any prior art reference or practice. As such, the inventors expressly disclaim this section as admitted or assumed prior art. Moreover, the identification herein of desirable courses of action reflects the inventors' own observations and ideas, and should not be assumed to indicate an art-recognized desirability.